Key Difference: Printer is a peripheral device that creates a solid copy of the digital data that is represented on the computer screen. Printers can be used to connect to a computer using a USB or wirelessly. Scanners, also known as image scanners, are peripheral device that is used to turn solid data into a digital data. These devices scan images, text, handwriting or objects and show them on a computer screen.

Printers and scanners are two different peripheral devices that can be connected to a computer. These two perform two different purposes, with one being able to turn digital data into print data, while the other can convert print data into digital data. These two devices are used for different purposes and have now become an important part of many businesses or households.

Printer is a peripheral device that creates a solid copy of the digital data that is represented on the computer screen. Printers can be used to connect to a computer using a USB or wirelessly. One printer can also be connected to many computers allowing all computers to be able to print on that printer. Many newer printers are also able to support memory cards, digital cameras or scanners. Higher end models for offices also come with other features such as scanner, copier and fax. These models are known as Multifunction printers.

There are various different kinds of printers that are available. These printers are classified depending on the type of technology is used in printing. Technology includes: Toner-based printers, Liquid inkjet printers, Solid ink printers, Dye-sublimation printers and Inkless printer. Toner-based printers use dry powered toner as ink, which is then fused on the paper by hot rollers. Liquid inkjet printers use liquid ink that is heated into a vapor bubble and then sprayed onto the paper. Solid ink printers use thermal transfer technology and use solid sticks of color that are wax-like in texture; these inks are melted and then sprayed on a rotating, oil coated drum, which passes the image onto the paper. A dye-sublimation printer uses heat to transfer dye to a medium such as a plastic card, paper or canvas. Inkless printer printers work by heating regions of a heat-sensitive paper that creates images or text on it.

Scanners, also known as image scanners, are peripheral device that is used to turn solid data into a digital data. These devices scan images, text, handwriting or objects and show them on a computer screen. Scanners connect to the computer using a USB that allows the scanner to sent the scanned data to the computer. There are three designs of scanners: flatbed scanner, hand-held scanner and rolling scanner. The flatbed scanner has a lid that can be opened and the image or object is placed on the glass and then scanned. Hand-held scanner allows using a wand to scan the object, while a rolling scanner required placing the paper through a roller, which then scans the paper and sends the text or image to the desktop. In newer devices, many scanners come with printers.

Modern scanners use two different types of technologies to scan an object: a charge-coupled device (CCD) or a Contact Image Sensor (CIS). Older drum scanners would use a photomultiplier tube as the image sensor. The latest scanner is a 3D scanner and printer that takes a scan of 3D objects and then prints the device in 3D itself. A CCD scanner has a glass pane placed on a bright light that illuminates the pane and a moving optical array. CCD scanners have three rows of sensors with different filters (red, blue and green). A CIS scanner has a moving set of red, blue and green LEDs that checks for illumination and a connected monochromatic photodiode array under a rod lens array for light collection. The scanner checks for the device by seeing which light is reflected, and then creates the image based on light reflection. Many cellphones these days offer scanning capabilities by taking a photo of the image. The scanning app whitens the background of the page, corrects perspective distortion, allows converting to black and white, etc. These use the camera exposures and then convert the data into a PDF document or a separate JPEG image.

The main difference between a printer and a scanner is the printer’s ability to covert digital data into a hardcopy, while a scanner takes a hard copy and converts into digital data. Each uses different methods for performing such tasks. Modern printers comes with a bunch of features including printer and scanner together, making it easier to scan documents or images and then directly printing them again.

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